The present invention relates generally to portable, cellular telephones and more specifically relates to grounding assemblies for such telephones that are operable to place the telephones into test modes.
The popularity and low cost of portable cellular telephones has increased tremendously in the past few years. Technology advances have reduced the size and cost of such telephones. One popular model of a portable cellular telephone is manufactured by Motorola, Inc. of Schaumburg, Ill. and sold under the trade names "Micro-Tac" and "Tele-Tac". The former is generically referred to by the public as a "flip-phone" because it has a speaker portion hinged to the telephone body that "flips" away from the body to expose the keypad to access. A rechargeable battery module interconnects to the rear of the telephone body and provides power for the telephone. The latter type of telephone has no hinged speaker component, but has the speaker built into the body portion of the telephone. However, it also uses a detachable battery module for powering the telephone.
These two cellular telephones, as well as all other cellular telephones in the marketplace contain a variety of programmable parameters that define the operation of cellular telephones. These parameters include, for example, the electronic serial number ("ESN") of the telephone, the telephone number (referred to as a mobile identification number or "MIN") assigned to the cellular telephone, the system identification number ("SIN") of the cellular system to which the user subscribes, confidential user codes and other important information. This information is held within a memory area of the cellular telephone that is known as a number assignment module ("NAM").
When a customer initially subscribes to a cellular service, this information is programmed into the NAM of the telephone at the point of purchase by the vendor. In order to program or read this information, the cellular telephone must be set to a test mode for access to the NAM. This information is stored in a memory of the telephone and any subsequent changes to this information is effected by accessing the NAM of the cellular telephone.
Unfortunately, the increase in popularity and reduction of cost in cellular telephones have also made such telephones attractive to thieves. Stolen telephones may be identified when recovered by law enforcement officials by placing the telephones into a test mode in the same manner as a telephone vendor does at the point of purchase to read the information contained in the NAM, such as the ESN, the MIN and other information.
The easiest manner to set a cellular telephone into a test mode is by grounding a manual test pin located on the telephone main body in opposition to its battery module. Presently, this task requires removing the battery module and placing the telephone body into a test receptacle or block having a regulated power supply and a momentary contact switch, or using a wire jumper to ground the manual test pin while applying power to the portable telephone. The telephone is then powered up by pressing its power key and a selected key of the keypad, such as the "#" key, is pressed to place the telephone into what is known as the manual test mode. Although effective, these test receptacles are expensive and cumbersome, while the wire jumper method is crude and requires the use of two hands which may preclude the tester from applying power to the telephone to enable its test mode. Neither of these two known manners of programming lend themselves to use by individual telephone owners or law enforcement officials.
Therefore, a need exists for a simple and inexpensive grounding mechanism that permits quick, one-handed access to the test mode of a cellular telephone for NAM programming and reading. The present invention is directed to a grounding assembly for portable cellular telephones that overcomes the aforementioned disadvantages and has a simple and low cost structure which can be utilized as a replacement battery module for cellular telephones.